The country fired the missiles into the East Sea (Sea of Japan) from its eastern city of Wonsan between 4:20-5:10 pm local time, a defence ministry spokesman told AFP.
They flew about 200 kilometres before landing.
"We are closely watching for any signs of additional missile launches by the North," said an official with the Joint Chiefs of Staff quoted by Yonhap news agency.
Yesterday, the North said it had test-fired an "ultra-precision" anti-ship rocket to be deployed across its navy under the guidance of leader Kim Jong-Un.